· Backup fails with: Warn: [broker/backups] unexpected error doing backup on FileBrowser.Entry: / : /Backup/RoonOneShot20260501/RoonBackups: Sooloos.SynchronizationContextThreadException: In Broker:Media ---> Sooloos.SynchronizationContextThreadException: In Broker:Transport ---> Sooloos.SynchronizationContextThreadException: In Broker:Misc ---> System.OutOfMemoryException: Array dimensions exceeded supported range.
The problem seems similar to the one signaled by Geoff_Coupe in https://community.roonlabs.com/t/backup-failure-due-to-potential-database-corruption-on-rock-nuc-system-ref-m8jtni/318778
My context: - Roon Server is on a Linux machine (Manjaro up to date, 32GB RAM) - the destination of backups is a second internal SSD (ext4), different from the one holding the database - I make nightly backups at 4:00 AM - all previous backups succeeded (until the 30 April included), with roonserver already in v2.65 - and before that all previous backups succeeded in v2.64 - the first failed backup is the programmed one of 1st May at 4:00 AM - I tried a standalone manual backup this morning : same failure - another try of manual backup after reboot of the machine : same failure - the failure is not immediate, but after ~45 sec (it looks like the verification phase is OK) - you can see the traces of that last attempt at 05/01 10:00:30
Another info which may have impact: - Before the failed backup (at 30th April 7PM), I made a restore of the 27th April 4:00 AM backup, which was the last one with v2.64 - this is related to a different support case: https://community.roonlabs.com/t/date-added-metadata-changed-for-half-of-albums-in-roon-2-65-ref-rgblx3/319062/10 - but I previously (27th April evening) made a restore of this same backup, and the following backups succeeded, so ... ?
Tell us about your home network
· roon server machine wired to the box/modem (fast optical fiber to Internet). Remotes (Android, desktop) through Wifi. No VPN.
Thanks for the detailed traces and for laying out the backup history so clearly. The stack you shared, along with the fact that the failure starts after about 45 seconds rather than immediately, gives us a useful place to start.
Today I installed Roon v2.66 and tried a manual backup (at 05/05 20:02:40) with the same error:
05/05 20:03:01 Warn: [broker/backups] unexpected error doing backup on FileBrowser.Entry: Backup, Samsung SSD 870 QVO 2TB : /RoonOneShot20260501/RoonBackups: Sooloos.SynchronizationContextThreadException: In Broker:Media
—> Sooloos.SynchronizationContextThreadException: In Broker:Transport
—> Sooloos.SynchronizationContextThreadException: In Broker:Misc
—> System.OutOfMemoryException: Array dimensions exceeded supported range.
at System.IO.MemoryStream.set_Capacity(Int32 value)
at System.IO.MemoryStream.EnsureCapacity(Int32 value)
at Sooloos.Broker.BackupCompute.<>c__DisplayClass12_1.b__1(String file, Boolean needs_copy)
at Sooloos.Broker.BackupCompute.<>c__DisplayClass12_1.b__4()
at Sooloos.SynchronizationContextThread.<>c__DisplayClass48_0.b__0()
— End of inner exception stack trace —
at Sooloos.SynchronizationContextThread.SendSafe(Action handler)
at Sooloos.Broker.BackupCompute.<>c__DisplayClass12_1.b__3()
at Sooloos.SynchronizationContextThread.<>c__DisplayClass48_0.b__0()
— End of inner exception stack trace —
at Sooloos.SynchronizationContextThread.SendSafe(Action handler)
at Sooloos.Broker.BackupCompute.<>c__DisplayClass12_1.b__2()
at Sooloos.SynchronizationContextThread.<>c__DisplayClass48_0.b__0()
— End of inner exception stack trace —
at Sooloos.SynchronizationContextThread.SendSafe(Action handler)
at Sooloos.Broker.BackupCompute.<>c__DisplayClass12_0.b__0()
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
— End of stack trace from previous location —
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
— End of stack trace from previous location —
at Sooloos.Broker.BackupCompute.ComputeBackupFiles(List1 filesinmanifest, List1 filestoupload, HashSet1 latesthashes, Canceler canceler) at Sooloos.Broker.BackupDestination1.StartBackup(Entry location, Nullable`1 numberofbackupskept, Boolean auto)
05/05 20:03:01 Debug: [broker/backups] on done, auto: False
If it may help, I can send you a copy of my database folder (done that for the other support case).
Thank you for the update and for testing this again on version 2.66. The new stack trace is very helpful.
Since the issue is still persisting, we would gladly take you up on your offer to send a copy of your database. Having the actual database will allow our development team to reproduce the exact OutOfMemoryException locally and see what is failing during the computation phase.
Are you able to access your database and zip up the entire database folder for us?
If you can zip up that folder and send us a copy here, we can get a much better sense of what’s going wrong.
Please let us know once the upload is complete, and we’ll take a closer look and walk you through the next steps!
We’ve discussed this with our senior QA and development teams. The team is investigating some possibilities here and, as soon as that investigation is complete, we’ll be sure to follow up ASAP.
You have our apologies for the trouble here, and we’ve greatly appreciated your patience as we continue investigating this tricky issue. We’ll be in touch as soon as we can.
For this “date added” metadata problem, @benjamin proposed a configuration modification at 11 PM April 30th, and I applied it soon after (around 1-2 AM May 1st). After many synchronization between my server and yours, the date problem was solved.
Then the automatic backup at 4 AM May 1st was the first to fail (and all the following one also, even with Roon v2.66) (see timetable bellow)
This could be an interesting clue to examine.
Date
Event
Status
Roon version
2026/04/26 4 AM
automatic backup
OK
2.64
2026/04/27 4 AM
automatic backup
OK
2.64
2026/04/28 4 AM
automatic backup
OK
2.65
2026/04/29 4 AM
automatic backup
OK
2.65
2026/04/30 4 AM
automatic backup
OK
2.65
2026/05/01 around 2 AM
Import Settings / “Import date defaults to” changed to “File Creation time”
The problem of incorrect “date added” attribute is solved by this change
A manual Roon backup just succeeded !
And I don’t know why …
Previously, all automatic (or manual) backups since May 1st failed; this morning at 4am also.
This evening I wanted to test if a cleaning of the database (from Roon GUI) may have a positive effect. So I stopped the roonserver service, copied (with tar) the /var/roon/RoonServer folder, and relaunched the service.
Then, before the cleaning of the database, I made a manual backup test, to confirm the problem; but it succeeded ! And I then forced an automatic backup : success again !
I still have to see if the automatic scheduled backup at 4am will be ok.
I have no explanation for this : in May I had several stop/start of the roonserver service, even a machine restart, and nothing improved the backup process failure.
Glad to hear the backup is working again. We did not make any changes, at least not as far as I am aware. Please keep us posted after a bit more testing, if the scheduled backups continue to succeed.
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